Doctors for rolls



April 1954 c. R. HUGHES 3,130,438

' DOCTORS FOR ROLLS Filed Aug. 2-0, 1962 2 SheetsSheet 1 23 INVENTOR.

CHARLES R. HUGE [J BY Mow/4m 5% V Zbw JUUEWFKC April 28, 1964 c HUGHES3,130,438

DOCTORS FOR ROLLS Filed Aug. 20, 1962 2 Sheets-Sheet 2 INVENTOR. CHARLESP. HUGHES ZLZ M w w A TTOPNE V5 United States Patent 3,130,438 DOCTORSFDR ROLLS Charles R. Hughes, 195 Burgess Drive, Galesburg, Mich. FiledAug. 29, 1962, Ser. No. 218,490 Claims. (Cl. -25653) This inventionrelates in general to an apparatus, including doctor blades, forremoving unwanted materials which are deposited upon the peripheralsurface of a roll and, more importantly, to a type of such apparatuswhich is more efficient and effective than those previously used. Thisapplication is a continuation-in-part of my copending application SerialNo. 70,010, filed November 17, 1960, and entitled Doctors for Rolls, nowabandoned.

It is well known that doctors or doctor blades have long been used inassociation with the rolls of various web forming machines, such aspapermaking machines or various ones of the machines for producingplastic films. Each doctor is usually comprised of an elongated bladewhich engages the peripheral surface of a selected roll in the webmakingmachine for the purpose of removing therefrom small particles which maybe deposited by the web as it moves over the rolls. If these particlesare not removed, they will often cause the machine to produce adefective Web.

In order to facflitate a full disclosure of the invention, reference ismade herein to the use of one embodiment of the invention in associationwith the rolls of a papermaking machine. However, it will be recognizedthat such reference is for illustrative purposes, only, and is notintended to limit the scope of the invention.

Where a papermaking machine is involved, for example, the web of papermoves around one side of the roll and the doctor blade is mounted sothat it engages the opposite side of the roll. It is customary to placea plurality of such rolls in vertical stacks with adjacent rolls intangential engagement. Accordingly, a plurality of doctors may berequired, said doctors being mounted for engagement with selected rollsin the stack. The doctors, which are often mounted upon the endstructures which support the rolls, are arranged for movement lengthwiseof the rotational axes of the rolls which they engage. This lengthwisemovement of the doctors loosens, or at least moves, deposits of foreignmaterials, which often collect along the engaging edge of the blade andthereby prevents annular scoring of the roll by those deposits which areabrasive. These concepts are well known in the art and have been usedfor many years. However, the existing mechanisms for effecting thelengthwise movement of the doctors have been cumbersome, difiicult tomaintain, expensive to install and even more difficult to adjust and tokeep in adjustment.

Accordingly, a primary object of this invention has een the provision ofan improved apparatus, including a doctor, for effectively removingforeign materials from the peripheral surface of a roll.

A further object of this invention has been the provision of apparatus,as aforesaid, including a plurality of doctor blades arrangedrespectively in association with a plurality of rolls and includingimproved, eflicient mecham'sm for effecting lengthwise movement of saiddoctor blades.

A further object of this invention has been the provision of anapparatus, as aforesaid, wherein the reciprocating movements of theseveral doctor blades are out of phase with each other in order toreduce the radial load upon the driving mechanism, and wherein theamount of lengthwise movement of said doctors can be quickly and easilyadjusted.

A further object of this invention has been the provision of anapparatus, as aforesaid, which is relatively simple 3,130,438 PatentedApr. 28, 1964 in construction which is completely foolproof in itsoperation, which requires a minimum of cost to manufacture and operateand which is more effective and efiicient in operation than previousdevices for the same or similar purposes.

Other objects and purposes of this invention will become apparent topersons familiar with this type of equipment upon reading the followingdescriptive material and examining the accompanying drawing, in which:

FIGURE 1 is a side elevational view of an apparatus, including aplurality of doctors, embodying the invention.

FIGURE 2 is an end elevational view of said apparatus.

FIGURE 3 is a broken sectional View taken along the line III III inFIGURE 1.

FIGURE 4 is a sectional View taken along the line lV-IV in FIGURE 1.

FIGURE 5 is a sectional view similar to that shown in FIGURE 4 with theparts in difierent positions of operation.

FIGURE 6 is a sectional View taken along the line VI-VI in FIGURE 1.

FIGURE 7 is a sectional view taken along the line VII-VII in FIGURE 1.

FIGURE 8 is a fragment of an apparatus similar to the apparatus shown inFIGURE 1, and disclosing an alternate structure for doctors embodyingthe invention.

FIGURE 9 is a sectional view substantially as taken along the line IXIXin FIGURE 8.

FIGURE 10 is a sectional view substantially as taken along the line XXin FIGURE 8.

FIGURE 11 is a sectional view taken along the line XIXI in FIGURE 10.

For convenience in description the terms upper, lower, left, right,front, rear and words of similar import, will have reference to amachine embodying the invention and the structure associated therewithas appearing in FIGURE 1, which discloses the front view of the machinein its normal position of operation. The terms inner, outer andderivatives thereof will have reference to the geometric center of saidmachine and parts associated therewith.

General Description The objects and purposes of the invention, includingthose set forth above, have been met by providing an apparatus includinga plurality of doctors which are mounted in association with an equalnumber of rolls for the purpose of engaging the peripheral surfaces ofsaid rolls and thereby removing foreign materials from said surfaces. Ina preferred embodiment, the doctors, which include elongatedroll-engaging blades, are mounted upon the end structures which supportthe rolls. Corresponding ends of the doctors are engaged by cam actuateddevices which effect lengthwise reciprocation of the doctors. The camsare mounted upon a shaft so that the lengthwise reciprocations of atleast some of the doctors are out of phase with each other. This reducesthe radial loads upon the bearings supporting the cam shaft, which maybe driven by a motor operating through a gear box.

The throw of each cam is preferably adjustable so that thereciprocations of the doctors may be varied. The doctor blades areresiliently urged against their respective rolls which, in thisparticular embodiment, are arranged in a vertical stack as part of apapermaking machine.

Detailed Construction The part of a machine 10, shown in FIGURE 1, has astack of parallel rolls I1, 12 and 13 which are rotatably supported uponand between the end structures 16 and 17. The apparatus 18 of theinvention includes a plurality of elongated doctors 19 and 19a supportedupon the end structures 16 and 17, and mechanism 22 connected to saiddoctors for reciprocating same lengthwise thereof.

In this particular embodiment of the invention, the upper end and lowerrolls 11 and 13, respectively, are calendar rolls separated by andengaged with an intermediate roll 12. The web 23 of paper passes aroundthe rear sides of the rolls 11 and 13 and around the front side of theintermediate roll 12. The doctors 19 and 19a are located along the frontsides of said rolls 11 and 13. The rolls 11, 12 and 13 are mounted uponthe end structures 16 and 17 by means such as the bearings 24. Thecalendar rolls 11 and 13 may be interconnected and appropriately drivenby means indicated schematically in broken lines at 26 in FIGURE 1.

The doctor 19 (FIGURES 1, 3 and 6) includes a substantially rigid,support rod 27, which is preferably circular in cross section. Said rod27 is mounted upon the end structures 16 adjacent the front side of theroll 11 by means of the bearings 28 and 28a which permit both rotationaland axial movement of the rod 27 with respect thereto. Two or moresleeves 32 (FIGURE 6) are mounted at spaced intervals upon the rod 27and are releasably held thereon by means, such as a set screw 33. Adoctor blade 34, which has a roll-engaging edge 36, is mounted upon thesleeve 32 and preferably extends substantially beyond both ends of theroll 11. Said doctor blade 34 has a pair of transverse slots 37extending therethrough. Screws 38 slidably extend through the slots 37for threaded engagement with the sleeves 32, whereby said blade 34 isadjustably secured to the sleeves 32.

The doctor blade 34 (FIGURE 3) has a pair of integral fingers 41 and 42extending from opposite lengthwise ends thereof adjacent to the edge 36.A pair of resilient elements, such as the spiral springs 43 and 43a, aresecured at one encLof each to the fingers 41, 42, respectively. Theother ends of said springs 43 and 4312 are connected respectively to thebrackets 46 and 47 (FIGURE 3) mounted upon the end structures 16 and 17,respectively. The springs 43 and 43a are under tension when the edge 36of the blade 34 is in engagement with the roll 11.

The doctor 19a, in this particular embodiment, may be substantiallyidentical in structure to the doctor 19 so that a detailed descriptionof the doctor 19a is unnecessary. Briefly, the doctor 19a includes a rod27a which is supported upon and between bearings 29 and 29a, which aremounted upon the end structures 16 and 17, respectively. The doctorblade 34a is mounted upon the rod 27a, as set forth above with respectto the doctor blade 34, and it has an edge 36a which is engageable withthe peripheral surface of the calendar roll 13. The edge 36a of thedoctor blade 34 is held against the roll 13 by means including thesprings 44 and 44a.

The drive mechanism 22 (FIGURES 1 and 2) includes a substantiallyvertical shaft 51, the lower end of which is connected to, and isrotatably supported upon, the output end of the gear box 52. The upperend of the shaft 51 is rotatably supported within a bearing 53 mountedupon the end structure 16 by means of a bearing support 54. The gear box52 is connected to a convenient drive means, such as the motor 56.

A cam 57 (FIGURES 4 and is mounted upon the vertical shaft, 51 adjacentthe extended leftward end of the rod 27. In this particular embodiment,the cam 57 is circular and it has a circular, eccentric opening 58 inwhich a circular adjustment member 59 is snugly, but rotatably andslidably, disposed. Said member 53 has an eccentric shaft opening 62,through which the shaft 51 is snugly received. The eccentricity of theshaft openings 62 is preferably identical to the eccentricity of theadjustment opening 58 whereby the eccentricity of the cam 57 can beadjusted in any amount from maximum eccentricity, as shown in FIGURE 4,to concentricity, as shown in FIGURE 5. The adjustment member 59 isreleasably secured upon the shaft 51 by a set screw 63, and the cam 57is releasably mounted upon the adjustment member 59 by a set screw 64.

The peripheral surface of the cam 57 is engaged by, and between, thearms 66 and 67 (FIGURES 3, 4 and 5) of a yoke 68, the stem of which isin the form of a sleeve 69 from which said arms extend. The sleeve 69 ismounted upon the leftward end of the rod 27 and secured thereto by meansincluding a set screw 71. A pair of wear plates 72 (FIGURE 4) aremounted upon the opposing surfaces of the arms 66 and 67 for engagementwith the cam 57.

The shaft 51 is drivingly connected to the rod 27a of the doctor 19a bya cam 57a and yoke 68a which may be arranged and constructed like theabove-described cam 57 and yoke 68.

. Operation In preparing the apparatus 18 for operation, the angle ofthe blade 34 with respect to the roll 11 may be altered by loosening thescrews 38 and shifting the doctor blade transversely of its rod, as maybe required, after which said screws are tightened. The screw 71 is thenloosened and the yoke 68 is readjusted upon the rod 27 so that the cam57 is properly aligned between the arms 66 and 67. The amplitude of thelengthwise reciprocation of the doctor blade 19 can be adjusted byloosening one or both of the set screws 63 and 64 and adjusting the cam57 or its adjustment member 59 or both, as may be required. Adjustmentof the blade 34a or the cam 57a may be effected in a similar manner.

Under normal circumstances, and according to the teachings of theinvention, it will be desirable to arrange the cam 57 and 57a, as wellas the adjustment members 59 therein, so that the throws or maximumeccentricities of said cams are arranged uniformly around the verticalam's of the shaft 51. That is, where two cams 57 and 57a are involved,for example, the maximum eccentricities thereof will be in oppositeradial directions or 180 out of phase. Where three cams are provided,then the eccentricities would preferably be arranged at 120 intervalsaround the shaft axis. In the same manner, four cams would be arrangedso that their maximum eccentricities would be at intervals around theshaft axis. Thus, the complete rotating unit, including the verticalshaft and the cams mounted thereon, can be arranged in dynamic balance.Moreover, the reciprocations of the various doctor blades will be phasedso that the wear upon the hearing 53 and the gear box 52, due to radialthrust, will be held to a minimum. Furthermore, phasing of thereciprocations of the doctors tends to minimize sympathetic vi brationsin the machine 10 and also permits the use of lighter duty, hence lessexpensive drive mechanism 22.

With the apparatus 18, including the doctors 19 and 19a, and the drivemechanism 22, assembled upon the machine .10 as shown in FIGURE 1 andproperly adjusted as discussed above, operation of the machine 10 iscommenced by the drive means 26. Thereafter, the operation of theapparatus 18 is initiated by energizing the motor 56 which causes thegear box 52 to rotate the shaft 51 and the cams 57 and 57a thereonwhereby the yokes 68 and 68a, hence the rods 27 and 27a, arereciprocated lengthwise of the rolls 11 and 13. The edges 36 and 36a areresiliently urged against the peripheral surfaces of the rolls 11 and 13by the springs 43, 43a, 44 and 44a for the purpose of removingundesirable materials deposited thereon during the normal operation ofthe machine 10 in producing the web 23.v

Alternate Construction The alternate matchine 10a includes three rolls11a, 12a and 13a which may be substantially the same as the rolls 11, 12and 13, respectively, in the machine 10 of FIGURE 2. A fourth roll 76 isshown below the roll 13:: in the alternate machine 10a. The doctors 77and 77a, in the alternate apparatus 78 of the invention, are operativelyassociated with the rolls 11a and 13a, respectively, to

5 perform the same function as set forth above with respect to thedoctors 19 and 19a.

The apparatus 78 also includes the drive mechanism 79 which functions inmuch the same manner as the drive mechanism 22 in the apparatus 18. Thatis, a vertical shaft 51a is rotatably mounted upon the end structure 16aby bearings 53a and the associated bearing supports 54a. The verticalshaft 51:: is connected at its lower end through the gear box 52a to themotor 56a. The rolls 11a, 12a, 13a and 76 are supported upon the endstructure 16a by bearings 82.

The doctor 77, for example (FIGURE 11), includes an elongated structuremember 83 having lengthwise flanges 84 and 85. An elongated doctor blade87 is supported by the bolts 88 upon, and lengthwise of, the flange 85so that one lengthwise edge 90 of the blade 87 engages the surface ofthe roll 11a. The doctor blade 87 has transverse slots 89 through whichthe bolts 88 extend for efiecting transverse adjustment of the bladetoward and away from the roll 11a. In this particular embodiment, theblade 87 is comprised of a relatively soft strip 91 which includes theedge 90, and a relatively stiff back plate 92, which holds the softstrip 91 in position with respect to and adjacent the flange 85. Thistype of blade is particularly useful with a roll of the type having afibrous or non-metallic surface. The soft strip 91 may, for example, befabricated from felt or the like.

The angle member 83 has at its opposite ends shaft means, such as thestub shaft 93 shown in FIGURES l and 11, which extend from the oppositeends of the angle member and substantially parallel therewith. The stubshaft 93 is rotatably and axially slidably supported within a bearing94, which is in turn supported by the bearing bracket 96 upon the endstructure 16a. Accordingly, the stub shaft 93, hence the doctor 77, canrotate around and move lengthwise of the common axis of the stub shaft93 and bearing 94.

A cam follower 97, having a yoke 93, is adjustably mounted upon theflange 84 of the angle member 83 for engagement with a cam 99 supportedupon the vertical shaft 51a. The cam 99 may be identical with the cam 57of the apparatus 18 (FIGURES 4 and 5). If the shaft 51a is rotated whenthe cam 99 is eccentric with respect thereto, said cam will operatethrough the cam follower 97 to effect a lengthwise reciprocation of thedoctor 77, just as rotation of shaft 51 (FIGURE 3) acts through cam 57to reciprocate the doctor 19.

The soft strip 91 of the doctor blade 87 is yieldably and adjustablyurged against the roll 11a (FIGURES 9 and 10) by a counterweight 162which is connected to the angle member $3 by the support rod 103. Morespecifically, the rod 103 is rigidly mounted at one end thereof upon theflange 84 so that said rod extends upwardly and outwardly from themember 83 and roll 11a. The counterweight 102 is slidably supported uponthe rod 193 for adjustment lengthwise thereof. A set screw 194 isprovided for holding the counterweight in a selected position lengthwiseof the support rod 103. The blade 87 is arranged so that it is urgedupwardly against the roll 11a by the downward urging of thecounterweight 1'92. Accordingly, by appropriate location of thecounterweight 102 along the support rod 163, adjustments can be made inthe amount of pressure with which the soft strip 91 is pressed againstthe periphery of the roll 11a.

The doctor 77a (FIGURE 8) may be and preferably is identical to thedoctor 77 in construction and in operation. More specifically, thedoctor 77a includes an angle member 83a supporting a doctor blade 37::having a soft strip 91a which is yieldably urged against the roll 13a bya counterweight 192a mounted upon a support rod 103a, which is rigidlyconnected to the angle member 83a. A cam follower 97a, which isconnected to the angle member 8301, engages a cam 99a mounted upon thevertical shaft 61a for effecting lengthwise reciprocation of the doctor77a. The cams 99 and 99a are preferably mounted upon the vertical shaft51a so that their eccentricities are in dynamic balance around the axisof the shaft, thereby minimizing the adverse effects of theireccentricities upon the bearings 53a. The operation of the apparatus 78is substantially the same as the operation of the apparatus 18, eventhough the pressure control provided by the counterweights 102 and 102aand the construction of the doctors 77 and 77a differ somewhat fromtheir corresponding elements in the apparatus 13. Moreover, in manysituations, the apparatus 78 is interchangeable with the apparatus 18,insofar as the purpose of operation and acceptability of performance areconcerned.

Although particular, preferred embodiments of the invention have beendisclosed herein for illustrative purposes, it will be understood thatvariations or modifications of such disclosure, which lie within thescope of the appended claims, are fully contemplated.

What is claimed is:

1. An apparatus for removing materials from the peripheral surface of arigid cylindrical device rotatably mounted upon and between a pair ofsupport structures, comprising:

an elongated, substantially rigid member having lateral edge meansengageable with said peripheral surface, said rigid member includingfirst shaft means secured to, and extending from the opposite ends of,said rigid member;

bracket means mounted upon said support structures,

said first shaft means being engaged and supported by said bracket meansfor axial movement with respect to said bracket means, said bracketmeans being arranged so that said edge means on said rigid member canmove toward and away from a position wherein said edge means is inengagement with, and extends substantially the full length of, theperipheral surface of said cylindrical device;

means secured to said rigid member for continuously urging said edgemeans of said rigid member against said peripheral surface;

an eccentric;

second shaft means rotatably supporting said eccentric near said rigidmember;

adjustment means connected to said eccentric for changing theeccentricity thereof with respect to said sec ond shaft means;

follower means engaged by said eccentric and rigidly connected to saidrigid member; and

drive means connected to said second shaft means for rotating same,whereby said eccentric is rotated and said follower means effects alengthwise reciprocation of said rigid member.

2. The structure of claim 1 wherein said substantially rigid memberincludes a relatively rigid and elongated back plate and an elongatedrelatively soft strip defining said lateral edge, said soft strip beingadjustably held with respect to said rigid member by said back plate foradjustment transversely of the lengthwise extent of said rigid member,whereby said lateral edge means can be adjusted with respect to theperipheral surface of the cylindrical device.

3. An apparatus for removing materials from the peripheral surface of acylindrical member rotatably mounted upon and between a pair of supportstructures, comprismg:

an elongated, substantially rigid member having lateral edge meansengageable with said peripheral surface; first shaft means secured to,and extending from the opposite ends of, said rigid member;

bracket means mounted upon said support structures,

said first shaft means being snugly engaged and supported by saidbracket means for axial movement with respect to said bracket means,said bracket means being arranged so that said edge means on said rigidmember can move toward and away from a position wherein said edge meansis in engagement with and extends substantially the full length of theperipheral surface of said cylindrical member;

yieldable means secured to said rigid member for continuously urgingsaid edge means of said rigid member against said peripheral surfaces;

an eccentric;

second shaft means rotatably supporting said eccentric close to saidfirst shaft means;

adjustment means connected to said eccentric for changing theeccentricity thereof with respect to said second shaft means;

follower means engaged by said eccentric and mounted upon said firstshaft means; and

drive means connected to said second shaft means for rotating same,whereby said eccentric is rotated and said follower means effects alengthwise reciprocation of said rigid member.

4. An apparatus for removing foreign materials from a the peripheralsurfaces of a plurality of rolls supported upon and between a pair ofupright structures, said rolls being axially horizontal and verticallyaligned, comprising:

a plurality of elongated, parallel and substantially rigid rods one ofsaid rods being disposed adjacent the peripheral surface of each rolland extending lengthwise thereof;

a plurality of bearing members arranged in coaxial pairs and mountedupon said support structures, the opposite end portions of each rodbeing disposed within a pair of said bearing members for rotational andaxial movement with respect thereto;

a plurality of elongated doctor blades, one blade being mounted uponeach rod for movement therewith, each blade having an elongated edgeengageable with the peripheral surface of the adjacent rollsubstantially throughout the length thereof;

resilient means connected between one of said support structures and theadjacent end of each blade for urging said edge against said peripheralsurface;

parallel arms engaging the opposite sides of one of said cams, wherebyrotation of said shaft effects lengthwise sequential reciprocation ofsaid rods and said doctor blades; and drive means connected to saidshaft for eflYecting rotation thereof. 5. The structure of claim 4wherein each cam is comprised of a pair of substantially cylindricalmembers having eccentrically disposed, circular openings therethrough,

the central axes of said openings being respectively parallel with thecentral axes of said cylindrical members, one member being rotatably andsnugly disposed within the circular opening in the other member and theeccentricities of said openings being substantially the same, wherebythe amount of eccentricity of the outer member with respect to saidshaft, which extends through the opening in the inner member, can beadjusted by rotating one of said members with respect to the other; and

screw means within each member whereby said outer member can be rigidlyheld with respect to the inner member and the inner member can bepositively secured upon said shaft.

Berry et al. Mar. 12, 1929 Edmondson July 13, 1943

1. AN APPARATUS FOR REMOVING MATERIALS FROM THE PERIPHERAL SURFACE OF ARIGID CYLINDRICAL DEVICE ROTATABLY MOUNTED UPON AND BETWEEN A PAIR OFSUPPORT STRUCTURES, COMPRISING: AN ELONGATED, SUBSTANTIALLY RIGID MEMBERHAVING LATERAL EDGE MEANS ENGAGEABLE WITH SAID PERIPHERAL SURFACE, SAIDRIGID MEMBER INCLUDING FIRST SHAFT MEANS SECURED TO, AND EXTENDING FROMTHE OPPOSITE ENDS OF, SAID RIGID MEMBER; BRACKET MEANS MOUNTED UPON SAIDSUPPORT STRUCTURES, SAID FIRST SHAFT MEANS BEING ENGAGED AND SUPPORTEDBY SAID BRACKET MEANS FOR AXIAL MOVEMENT WITH RESPECT TO SAID BRACKETMEANS, SAID BRACKET MEANS BEING ARRANGED SO THAT SAID EDGE MEANS ON SAIDRIGID MEMBER CAN MOVE TOWARD AND AWAY FROM A POSITION WHEREIN SAID EDGEMEANS IS IN ENGAGEMENT WITH, AND EXTENDS SUBSTANTIALLY THE FULL LENGTHOF, THE PERIPHERAL SURFACE OF SAID CYLINDRICAL DEVICE; MEANS SECURED TOSAID RIGID MEMBER FOR CONTINUOUSLY URGING SAID EDGE MEANS OF SAID RIGIDMEMBER AGAINST SAID PERIPHERAL SURFACE;